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1.1 root 1: /*
2: * This program implements the
3: * Proposed Federal Information Processing
4: * Data Encryption Standard.
5: * See Federal Register, March 17, 1975 (40FR12134)
6: */
7:
8: /*
9: * Initial permutation,
10: */
11: static char IP[] = {
12: 58,50,42,34,26,18,10, 2,
13: 60,52,44,36,28,20,12, 4,
14: 62,54,46,38,30,22,14, 6,
15: 64,56,48,40,32,24,16, 8,
16: 57,49,41,33,25,17, 9, 1,
17: 59,51,43,35,27,19,11, 3,
18: 61,53,45,37,29,21,13, 5,
19: 63,55,47,39,31,23,15, 7,
20: };
21:
22: /*
23: * Final permutation, FP = IP^(-1)
24: */
25: static char FP[] = {
26: 40, 8,48,16,56,24,64,32,
27: 39, 7,47,15,55,23,63,31,
28: 38, 6,46,14,54,22,62,30,
29: 37, 5,45,13,53,21,61,29,
30: 36, 4,44,12,52,20,60,28,
31: 35, 3,43,11,51,19,59,27,
32: 34, 2,42,10,50,18,58,26,
33: 33, 1,41, 9,49,17,57,25,
34: };
35:
36: /*
37: * Permuted-choice 1 from the key bits
38: * to yield C and D.
39: * Note that bits 8,16... are left out:
40: * They are intended for a parity check.
41: */
42: static char PC1_C[] = {
43: 57,49,41,33,25,17, 9,
44: 1,58,50,42,34,26,18,
45: 10, 2,59,51,43,35,27,
46: 19,11, 3,60,52,44,36,
47: };
48:
49: static char PC1_D[] = {
50: 63,55,47,39,31,23,15,
51: 7,62,54,46,38,30,22,
52: 14, 6,61,53,45,37,29,
53: 21,13, 5,28,20,12, 4,
54: };
55:
56: /*
57: * Sequence of shifts used for the key schedule.
58: */
59: static char shifts[] = {
60: 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1,
61: };
62:
63: /*
64: * Permuted-choice 2, to pick out the bits from
65: * the CD array that generate the key schedule.
66: */
67: static char PC2_C[] = {
68: 14,17,11,24, 1, 5,
69: 3,28,15, 6,21,10,
70: 23,19,12, 4,26, 8,
71: 16, 7,27,20,13, 2,
72: };
73:
74: static char PC2_D[] = {
75: 41,52,31,37,47,55,
76: 30,40,51,45,33,48,
77: 44,49,39,56,34,53,
78: 46,42,50,36,29,32,
79: };
80:
81: /*
82: * The C and D arrays used to calculate the key schedule.
83: */
84:
85: static char C[28];
86: static char D[28];
87: /*
88: * The key schedule.
89: * Generated from the key.
90: */
91: static char KS[16][48];
92:
93: /*
94: * Set up the key schedule from the key.
95: */
96:
97: setkey(key)
98: char *key;
99: {
100: register i, j, k;
101: int t;
102:
103: /*
104: * First, generate C and D by permuting
105: * the key. The low order bit of each
106: * 8-bit char is not used, so C and D are only 28
107: * bits apiece.
108: */
109: for (i=0; i<28; i++) {
110: C[i] = key[PC1_C[i]-1];
111: D[i] = key[PC1_D[i]-1];
112: }
113: /*
114: * To generate Ki, rotate C and D according
115: * to schedule and pick up a permutation
116: * using PC2.
117: */
118: for (i=0; i<16; i++) {
119: /*
120: * rotate.
121: */
122: for (k=0; k<shifts[i]; k++) {
123: t = C[0];
124: for (j=0; j<28-1; j++)
125: C[j] = C[j+1];
126: C[27] = t;
127: t = D[0];
128: for (j=0; j<28-1; j++)
129: D[j] = D[j+1];
130: D[27] = t;
131: }
132: /*
133: * get Ki. Note C and D are concatenated.
134: */
135: for (j=0; j<24; j++) {
136: KS[i][j] = C[PC2_C[j]-1];
137: KS[i][j+24] = D[PC2_D[j]-28-1];
138: }
139: }
140: }
141:
142: /*
143: * The E bit-selection table.
144: */
145: static char E[48];
146: static char e[] = {
147: 32, 1, 2, 3, 4, 5,
148: 4, 5, 6, 7, 8, 9,
149: 8, 9,10,11,12,13,
150: 12,13,14,15,16,17,
151: 16,17,18,19,20,21,
152: 20,21,22,23,24,25,
153: 24,25,26,27,28,29,
154: 28,29,30,31,32, 1,
155: };
156:
157: /*
158: * The 8 selection functions.
159: * For some reason, they give a 0-origin
160: * index, unlike everything else.
161: */
162: static char S[8][64] = {
163: 14, 4,13, 1, 2,15,11, 8, 3,10, 6,12, 5, 9, 0, 7,
164: 0,15, 7, 4,14, 2,13, 1,10, 6,12,11, 9, 5, 3, 8,
165: 4, 1,14, 8,13, 6, 2,11,15,12, 9, 7, 3,10, 5, 0,
166: 15,12, 8, 2, 4, 9, 1, 7, 5,11, 3,14,10, 0, 6,13,
167:
168: 15, 1, 8,14, 6,11, 3, 4, 9, 7, 2,13,12, 0, 5,10,
169: 3,13, 4, 7,15, 2, 8,14,12, 0, 1,10, 6, 9,11, 5,
170: 0,14, 7,11,10, 4,13, 1, 5, 8,12, 6, 9, 3, 2,15,
171: 13, 8,10, 1, 3,15, 4, 2,11, 6, 7,12, 0, 5,14, 9,
172:
173: 10, 0, 9,14, 6, 3,15, 5, 1,13,12, 7,11, 4, 2, 8,
174: 13, 7, 0, 9, 3, 4, 6,10, 2, 8, 5,14,12,11,15, 1,
175: 13, 6, 4, 9, 8,15, 3, 0,11, 1, 2,12, 5,10,14, 7,
176: 1,10,13, 0, 6, 9, 8, 7, 4,15,14, 3,11, 5, 2,12,
177:
178: 7,13,14, 3, 0, 6, 9,10, 1, 2, 8, 5,11,12, 4,15,
179: 13, 8,11, 5, 6,15, 0, 3, 4, 7, 2,12, 1,10,14, 9,
180: 10, 6, 9, 0,12,11, 7,13,15, 1, 3,14, 5, 2, 8, 4,
181: 3,15, 0, 6,10, 1,13, 8, 9, 4, 5,11,12, 7, 2,14,
182:
183: 2,12, 4, 1, 7,10,11, 6, 8, 5, 3,15,13, 0,14, 9,
184: 14,11, 2,12, 4, 7,13, 1, 5, 0,15,10, 3, 9, 8, 6,
185: 4, 2, 1,11,10,13, 7, 8,15, 9,12, 5, 6, 3, 0,14,
186: 11, 8,12, 7, 1,14, 2,13, 6,15, 0, 9,10, 4, 5, 3,
187:
188: 12, 1,10,15, 9, 2, 6, 8, 0,13, 3, 4,14, 7, 5,11,
189: 10,15, 4, 2, 7,12, 9, 5, 6, 1,13,14, 0,11, 3, 8,
190: 9,14,15, 5, 2, 8,12, 3, 7, 0, 4,10, 1,13,11, 6,
191: 4, 3, 2,12, 9, 5,15,10,11,14, 1, 7, 6, 0, 8,13,
192:
193: 4,11, 2,14,15, 0, 8,13, 3,12, 9, 7, 5,10, 6, 1,
194: 13, 0,11, 7, 4, 9, 1,10,14, 3, 5,12, 2,15, 8, 6,
195: 1, 4,11,13,12, 3, 7,14,10,15, 6, 8, 0, 5, 9, 2,
196: 6,11,13, 8, 1, 4,10, 7, 9, 5, 0,15,14, 2, 3,12,
197:
198: 13, 2, 8, 4, 6,15,11, 1,10, 9, 3,14, 5, 0,12, 7,
199: 1,15,13, 8,10, 3, 7, 4,12, 5, 6,11, 0,14, 9, 2,
200: 7,11, 4, 1, 9,12,14, 2, 0, 6,10,13,15, 3, 5, 8,
201: 2, 1,14, 7, 4,10, 8,13,15,12, 9, 0, 3, 5, 6,11,
202: };
203:
204: /*
205: * P is a permutation on the selected combination
206: * of the current L and key.
207: */
208: static char P[] = {
209: 16, 7,20,21,
210: 29,12,28,17,
211: 1,15,23,26,
212: 5,18,31,10,
213: 2, 8,24,14,
214: 32,27, 3, 9,
215: 19,13,30, 6,
216: 22,11, 4,25,
217: };
218:
219: /*
220: * The current block, divided into 2 halves.
221: */
222: static char L[32], R[32];
223: static char tempL[32];
224: static char f[32];
225:
226: /*
227: * The combination of the key and the input, before selection.
228: */
229: static char preS[48];
230:
231: /*
232: * The payoff: encrypt a block.
233: */
234:
235: encrypt(block, edflag)
236: char *block;
237: {
238: int i, ii;
239: register t, j, k;
240:
241: /*
242: * First, permute the bits in the input
243: */
244: for (j=0; j<64; j++)
245: L[j] = block[IP[j]-1];
246: /*
247: * Perform an encryption operation 16 times.
248: */
249: for (ii=0; ii<16; ii++) {
250: /*
251: * Set direction
252: */
253: if (edflag)
254: i = 15-ii;
255: else
256: i = ii;
257: /*
258: * Save the R array,
259: * which will be the new L.
260: */
261: for (j=0; j<32; j++)
262: tempL[j] = R[j];
263: /*
264: * Expand R to 48 bits using the E selector;
265: * exclusive-or with the current key bits.
266: */
267: for (j=0; j<48; j++)
268: preS[j] = R[E[j]-1] ^ KS[i][j];
269: /*
270: * The pre-select bits are now considered
271: * in 8 groups of 6 bits each.
272: * The 8 selection functions map these
273: * 6-bit quantities into 4-bit quantities
274: * and the results permuted
275: * to make an f(R, K).
276: * The indexing into the selection functions
277: * is peculiar; it could be simplified by
278: * rewriting the tables.
279: */
280: for (j=0; j<8; j++) {
281: t = 6*j;
282: k = S[j][(preS[t+0]<<5)+
283: (preS[t+1]<<3)+
284: (preS[t+2]<<2)+
285: (preS[t+3]<<1)+
286: (preS[t+4]<<0)+
287: (preS[t+5]<<4)];
288: t = 4*j;
289: f[t+0] = (k>>3)&01;
290: f[t+1] = (k>>2)&01;
291: f[t+2] = (k>>1)&01;
292: f[t+3] = (k>>0)&01;
293: }
294: /*
295: * The new R is L ^ f(R, K).
296: * The f here has to be permuted first, though.
297: */
298: for (j=0; j<32; j++)
299: R[j] = L[j] ^ f[P[j]-1];
300: /*
301: * Finally, the new L (the original R)
302: * is copied back.
303: */
304: for (j=0; j<32; j++)
305: L[j] = tempL[j];
306: }
307: /*
308: * The output L and R are reversed.
309: */
310: for (j=0; j<32; j++) {
311: t = L[j];
312: L[j] = R[j];
313: R[j] = t;
314: }
315: /*
316: * The final output
317: * gets the inverse permutation of the very original.
318: */
319: for (j=0; j<64; j++)
320: block[j] = L[FP[j]-1];
321: }
322:
323: char *
324: crypt(pw,salt)
325: char *pw;
326: char *salt;
327: {
328: register i, j, c;
329: int temp;
330: static char block[66], iobuf[16];
331: for(i=0; i<66; i++)
332: block[i] = 0;
333: for(i=0; (c= *pw) && i<64; pw++){
334: for(j=0; j<7; j++, i++)
335: block[i] = (c>>(6-j)) & 01;
336: i++;
337: }
338:
339: setkey(block);
340:
341: for(i=0; i<66; i++)
342: block[i] = 0;
343:
344: for(i=0;i<48;i++)
345: E[i] = e[i];
346:
347: for(i=0;i<2;i++){
348: c = *salt++;
349: iobuf[i] = c;
350: if(c>'Z') c -= 6;
351: if(c>'9') c -= 7;
352: c -= '.';
353: for(j=0;j<6;j++){
354: if((c>>j) & 01){
355: temp = E[6*i+j];
356: E[6*i+j] = E[6*i+j+24];
357: E[6*i+j+24] = temp;
358: }
359: }
360: }
361:
362: for(i=0; i<25; i++)
363: encrypt(block,0);
364:
365: for(i=0; i<11; i++){
366: c = 0;
367: for(j=0; j<6; j++){
368: c <<= 1;
369: c |= block[6*i+j];
370: }
371: c += '.';
372: if(c>'9') c += 7;
373: if(c>'Z') c += 6;
374: iobuf[i+2] = c;
375: }
376: iobuf[i+2] = 0;
377: if(iobuf[1]==0)
378: iobuf[1] = iobuf[0];
379: return(iobuf);
380: }
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